Filter
Top Products
9-4 User’s Reference Guide
Exterior addresses are allocated to internal hosts on a demand, or as-needed, basis and then made available
when traffic from that host ceases. Once an internal host has been allocated an address, it will use that
address for all traffic. Five minutes after all traffic ceases – no pings, all tcp connections closed, no DNS
requests, etc. – the address is put at the head of an available list. If an interior host needs an exterior address
an hour later, and the previously used address is still available, it will acquire the same address. If an interior
host that has not previously been allocated an exterior address needs one, it will be allocated the last, hence
the oldest, exterior address on the available list.
All NAT configurations are rule-based. This means that traffic passed through NAT from either the public or the
private network is compared to the rules and mappings configured in the Netopia R310 in a particular order.
The first rule that applies to the traffic being initiated is used.
For example, if a connection is initiated from the public network and is destined for a public IP address
configured on the Netopia R310, the following comparisons are made in this order.
■ The Netopia R310 first checks its internal NAT cache to see if the data is part of a previously initiated
connection, if not…
■ The Netopia R310 checks the configured Server Lists to see if this traffic is intended to be forwarded to an
internal host based on the type of service.
■ The Netopia R310 then checks to see if there is a Static, Dynamic, or PAT mapping for the public IP
address that the connection is being initiated to.
■ The Netopia R310 answers the request itself if the data is destined for the Netopia’s WAN interface IP
address. Otherwise the data is discarded.
Complex maps
Map Lists and Server Lists are completely independent of each other. A Connection Profile can use one or the
other or both.
MultiNAT allows complex mapping and requires seomwhat complex configuration. Multiple mapped interior
subnets are supported, and the rules for mapping each of the subnets may be different. The figure below
illustrates a possible multiNAT configuration.
172.16.1.25
172.16.1.26
172.16.1.27
172.16.1.28
172.16.1.29
Network Address Translation
Available for Dynamic NAT Used for Normal NAT
192.168.1.16
192.168.1.15
192.168.1.14
192.168.1.13
192.168.1.12
192.168.1.11
192.168.1.10
192.168.1.9
192.168.1.8
192.168.1.7
192.168.1.6
192.168.1.5
192.168.1.4
192.168.1.3
192.168.1.2
WAN Network
LAN Network